Cable television networks such as those provided by Comcast Cable Communications, Inc., of Philadelphia, Pa., Cox Communications of Atlanta, Ga., Tele-Communications, Inc., of Englewood Colo., Time-Warner Cable, of Marietta Ga., Continental Cablevision, Inc., of Boston Mass., and others provide cable television services to a large number of subscribers over a large geographical area. The cable television networks typically are interconnected by cables such as coaxial cables or a Hybrid Fiber/Coaxial (“HFC”) cable system which have data rates of about 10 Mega-bits-per-second (“Mbps”) to about 30+Mbps.
The Internet, a world-wide-network of interconnected computers, provides multi-media content including audio, video, graphics and text that typically requires a large bandwidth for downloading and viewing. Most Internet Service Providers (“ISPs”) allow customers to connect to the Internet via a serial telephone line from a Public Switched Telephone Network (“PSTN”) at data rates including 14,400 bps, 28,800 bps, 33,600 bps, 56,000 bps and others that are much slower than the about 10 Mbps to about 30+Mbps available on a coaxial cable or HFC cable system on a cable television network.
With the explosive growth of the Internet, many customers have desired to use the larger bandwidth of a cable television network to connect to the Internet and other computer networks.
Cable modems, such as those provided by 3Com Corporation, of Santa Clara, Calif., Motorola Corporation, of Arlington Heights, Ill., Hewlett-Packard Co., of Palo Alto, Calif., Bay Networks, of Santa Clara, Calif., Scientific-Atlanta, of Norcross, Ga. and others offer customers higher-speed connectivity to the Internet, an intranet, Local Area Networks (“LANs”) and other computer networks via cable television networks. These cable modems currently support a data connection to the Internet and other computer networks via a cable television network with a data rate of up to about 30+Mbps, which is a much larger data rate than can be supported by a modem used over a serial telephone line.
However, many cable television networks provide only unidirectional cable systems, supporting only a “downstream” cable data path. A downstream data path is the flow of data from a cable system “headend” to a customer. A cable system headend is a central location in the cable television network that is responsible for sending cable signals in the downstream direction. A return data path via a telephone network (i.e., a “telephony return”), such as a public switched telephone network provided by AT&T, GTE, Sprint, MCI and others, is typically used for an “upstream” data path. An upstream data path is the flow of data from the customer back to the cable system headend. A cable television system with an upstream connection to a telephony network is called a “data-over-cable system with telephony return.”
An exemplary data-over-cable system with telephony return includes customer premise equipment (e.g., a customer computer), a cable modem, a cable modem termination system, a cable television network, a public switched telephone network, a telephony remote access concentrator and a data network (e.g., the Internet). The cable modem termination system and the telephony remote access concentrator together are called a “telephony return termination system.”
The cable modem termination system receives data packets from the data network and transmits them downstream via the cable television network to a cable modem attached to the customer premise equipment. The customer premise equipment sends response data packets to the cable modem, which sends response data packets upstream via public switched telephone network to the telephony remote access concentrator, which sends the response data packets back to the appropriate host on the data network.
In a two-way cable system without telephony return, the customer premise equipment sends response data packets to the cable modem, which sends the data packets upstream via the cable television network to the cable modem termination system. The cable modem termination system sends the data packets to appropriate hosts on the data network. The cable modem termination system sends the response data packets back to the appropriate cable modem.
As a cable modem is initialized in a data-over-cable system, it registers with a cable modem termination system to allow the cable modem to receive data over a cable television connection and from a data network (e.g., the Internet or an Intranet). The cable modem forwards configuration information it receives in a configuration file during initialization to the cable modem termination system as part of a registration request message. A cable modem also helps initialize and register any attached customer premise equipment with the cable modem termination system.
A cable modem termination system in a data-over-cable system typically manages connections to tens of thousands of cable modems. Most of the cable modems are attached to host customer premise equipment such as a customer computer. To send and receive data to and from a computer network like the Internet or an intranet, a cable modem and customer premise equipment and other network devices have a network address dynamically assigned on the data-over-cable system. Many data-over-cable systems use a Dynamic Host Configuration Protocol (“DHCP”) as a standard messaging protocol to dynamically allocate network addresses such as Internet Protocol (“IP”) addresses. As is known in the art, the Dynamic Host Configuration Protocol is a protocol for passing configuration information to network devices on a network. The Internet Protocol is an addressing protocol designed to route traffic within a network or between networks.
A cable modem termination system typically handles requests for services on the data-over-cable system cable modems and customer premise equipment. As is known in the art, a Multimedia Cable Network System (“MCNS”) Data Over Cable Service Interface Specification system (“DOCSIS”) is typically used on some data-over-cable systems to define server interfaces that allow data services on a session basis. A session based data service is typically provided to a network device such as a cable modem or customer premise equipment during a one-time login and registration. The data service is typically available, or “always on,” as long as the network device is powered on.
A Remote Authentication Dial In User Server (“RADIUS”) server one is one example of an interface used by the DOCSIS system to provide data or other services to a network device. As is known in the art, RADIUS servers are responsible for receiving user connection requests, authenticating users, and then returning configuration information necessary for a client to deliver a service to a user. A RADIUS server can act as a proxy client to other RADIUS servers or other kinds of authentication servers (e.g., a Voice over Internet Protocol server, Dynamic Host Configuration server, a cable modem termination system, etc.).
Data services and other services such as Voice over Internet Protocol (“VoIp”), Asynchronous Transport Mode (“ATM”), Frame Relay, Integrated Services Digital Network (“ISDN”), Asymetric Digital Subscriber Lines (“ADSL”) with configurable Quality-of-Service (“QoS”), Class-of-Service (“CoS”), Type-of-Service (“ToS”), etc. parameters are typically also session based. When a network device desires a data or other service, a DOCSIS system server is typically used to provide authentication, authorization and/or accounting for assigning a data service used by a network device during a service session.
There are several problems associated with using a DOCSIS system server or other non-DOCSIS to allow a data service during a session on a data-over-cable system. A session is typically created once during a login and registration sequence, and not changed as long as the network device is “powered on.” For example, for Voice over Internet Protocol, a network device would typically require a session where a voice call could be completed at any time. One solution is to allow a network device that requires a session to have a maximum number of service parameters and service resources allocated to the session whether or not the network device is actually using a requested service. However, this may waste services resources on the data-over-cable system and prevent other network devices from using resources that are allocated, but are not currently being used by a network device.
It is also typically necessary to provide authentication, authorization or accounting at a DOCSIS system server or other non-DOCSIS when a service session is created. If a requested service requires additional service agreements, additional authentication, authorization or accounting has to be completed. However, the authentication, authorization or accounting is typically associated with a login request to initiate a service session. So requesting additional services after a service session is established may prevent authentication, authorization or accounting from being properly used by current DOCSIS system servers or other non-DOCSIS servers and may compromise the security of the data-over-cable system or prevent the data-over-cable system from collecting revenues it is owed for providing access to a service.
Thus, it is desirable to dynamically provide service session based services after a session has already been established by a network device. The dynamic service session based services should provide the ability to activate session-based services and also allow authentication, authorization or accounting to be dynamically used after a session has already been established by a network device.